Netherlands' Robin van Persie (L) picked up the injury during their World Cup 2014 qualifying match at Puskas Stadium in Budapest
Sir Alex Ferguson is sweating on the fitness of Manchester United duo Robin van Persie and Shinji Kagawa picked up injuries that forced them out of the action in Tuesday night's World Cup qualifiers.
Kagawa was left out by Japan coach Alberto Zaccheroni for the 1-0 win as a precaution after suffering a problem with his lower back, reports the BBC.
Van Persie was taken off at half-time with a suspected thigh injury in Holland’s 4-1 World Cup qualifying win in Hungary.
Kagawa has played down fears over the back injury and is confident the problem is not serious and does not expect to be on the sidelines for too long.
"I felt a twinge in the back during practice when I was on the ball. I had some treatment but didn't want to risk causing the team trouble by playing," Kagawa told the Kyodo news agency.
"Obviously it's a shame I wasn't able to play... It's not that serious and I don't think it will keep me out for long."
Ferguson will be hoping Kagawa can recover from the problem in time for Saturday's Premier League clash with Wigan and the start of the Champions League next week.
The United boss is already without Wayne Rooney who suffered a gash in his thigh against Fulham while Jonny Evans has yet to feature this season following ankle surgery.
Holland coach, Louis van Gaal played down Van Persie's substitution, telling SBS6: "We took off Robin for precautionary measures. It doesn't seem to be too serious, but you never know. We didn't want to take any risks."
The 29-year-old has netted four goals in three games for Manchester United following his transfer from Arsenal last month.
Van Persie also scored in Netherlands' 2-0 World Cup qualifying victory against Turkey on Friday.